Method and apparatus for reshaping a ventricle

ABSTRACT

Methods are provided for reshaping the left ventricle to a more conical shape to counter the effects of dilation, thereby improving pumping efficiency. In an exemplary embodiment, a reshaping apparatus comprises an implantable body that can be delivered to a dilated left ventricle via the patient&#39;s vasculature in a minimally-invasive procedure. When deployed inside the left ventricle, the implantable body applies a longitudinal (downward) force against the inner surface of the left ventricle, thereby causing the left ventricle to distend or elongate downwardly. The implantable body preferably includes an anchor which is deployed adjacent the mitral valve for maintaining the longitudinal force against the inner surface of the left ventricle.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a divisional of U.S. application Ser. No.14/524,950, filed Oct. 27, 2014, which is a continuation of U.S.application Ser. No. 13/252,060, filed Oct. 3, 2011, now U.S. Pat. No.8,870,936, which is a continuation of U.S. application Ser. No.11/695,583, filed Apr. 2, 2007, now U.S. Pat. No. 8,029,556, whichclaims the benefit of U.S. Provisional Application No. 60/849,242, filedOct. 4, 2006.

FIELD

The present invention relates to medical devices and methods and, moreparticularly, to a medical device and method for treating a dilatedventricle.

BACKGROUND

A healthy left ventricle of a human heart, which is the primary pumpingchamber, is generally conical or apical in shape in that it is longer(along a longitudinal axis extending in a direction from the aorticvalve to the apex) than it is wide (along a transverse axis extendingbetween opposing walls at the widest point of the left ventricle) anddescends from a base with a decreasing cross-sectional circumference toa point or apex. The pumping of blood from the left ventricle isaccomplished by a squeezing motion and a twisting or torsional motion.

The squeezing motion occurs between the lateral wall of the leftventricle and the septum. The twisting motion is a result of heartmuscle fibers that extend in a circular or spiral direction around theheart. When these fibers contract, they produce a gradient of angulardisplacements of the myocardium from the apex to the base about thelongitudinal axis of heart. The resultant force vectors extend at anglesfrom about 30 to 60 degrees to the flow of blood through the aorticvalve. The contraction of the heart is manifested as a counterclockwiserotation of the apex relative to the base, when viewed from the apex. Ahealthy heart can pump blood from the left ventricle in a very efficientmanner due to the spiral contractility of the heart.

Chronic congestive heart failure and other disease processes can causethe heart to enlarge or dilate from a conical shape to a shorter andwider shape, which in turn causes the muscle fibers to becomereoriented. As a result of the dilation, the orientation of the musclefibers produces lines of force directed generally laterally of the leftventricle at about 90 degrees relative to the outward flow of the blood.Hence, blood is pushed inwardly (toward the center of the leftventricle), rather than at an acute angle relative to the outward bloodflow, thereby greatly reducing the pumping efficiency of the leftventricle. In a similar manner, dilation of the heart also can adverselyaffect the function of the right ventricle.

A variety of treatment procedures have been proposed over the years fortreating left ventricular dilatation. However, these procedurestypically involve radical open-heart surgeries designed to surgicallyreduce the volume of the left ventricle. In recent years, several newminimally invasive techniques for improving heart function have beenproposed that do not require opening the chest or cardiopulmonaryby-pass. However, none of these procedures has gained widespreadacceptance and most fail to address the underlying cause of the problem.

Accordingly, an urgent need exists for a new device and method fortreating left ventricular dilatation.

SUMMARY

According to one aspect, the present disclosure concerns embodiments ofa reshaping apparatus and methods for restoring the conical shape of adilated heart ventricle, or at least reshaping the ventricle to a moreconical shape to counter the effects of dilation, thereby improvingpumping efficiency. In particular embodiments, the left ventricle isreshaped in a non-surgical or minimally-invasive procedure withoutopening the chest or cardiopulmonary by-pass. The shape of the leftventricle can be altered by applying a longitudinal force to the apex ofthe left ventricle to move the apex downward (relative to the base ofthe heart), such as by pushing or pulling the apex downwardly. Byapplying such a force (i.e., pushing or pulling) on the apex, the leftventricle becomes longer and thinner and thereby achieves a more conicalshape. As a result, the muscle fibers are better oriented to accomplishtorsional motion of the heart, thereby increasing the efficiency andwork capability of the left ventricle. The embodiments disclosed hereincan also be used to reshape a dilated right ventricle of the heart.

A reshaping device according to one exemplary embodiment comprises animplantable body that can be delivered to a dilated left ventricle viathe patient's vasculature in a minimally-invasive procedure. Whendeployed inside the left ventricle, the body is adapted to apply alongitudinal (downward) force against the inner surface of the leftventricle that causes the ventricle to distend or elongate downwardlyrelative to the base of the heart so as to at least partially restorethe conical shape of the heart. The body can include a radiallycompressible and expandable anchor member and an elongated pusher thatextends from the anchor member. The anchor member can have aconfiguration similar to that of a conventional stent and can bedeployed within the left ventricular outflow tract, for example justbelow the aortic valve. Once deployed, the pusher member extendsdownwardly from the anchor member and has a distal end portion thatengages and pushes against the inner surface of the left ventricle.

In one alternative embodiment, the reshaping device may comprise anelongate pusher member and an anchor member configured to apply alateral force against the surrounding tissue, which is effective to movethe anterior leaflet of the mitral valve toward the posterior leafletfor improving leaflet coaption, thereby reducing or eliminating mitralvalve regurgitation. In another embodiment, the reshaping device maycomprise an elongate pusher member and an anchor member in the form of aprosthetic valve assembly configured for deployment within the aorticannulus. In this embodiment, the reshaping device can be used to replacethe function of the aortic valve as well as to reshape the leftventricle to counter the effects of dilation.

In other alternative embodiments, a reshaping apparatus for reshaping adilated ventricle can include one or more tension members, such assuture lines, that are connected to tissue at opposing locations insidethe ventricle. The tension members are placed in tension to pull theopposing walls of the ventricle into closer proximity to reshape thedilated ventricle. For example, each tension member can be a suture loopthat extends through tissue at opposite locations on the inner walls ofthe ventricle. Alternatively, the tension members can be secured to theinner walls of the ventricle using self-deploying anchor members thatcan be deployed within the ventricle using a delivery catheter. Afterthe anchor members are deployed at predetermined locations within theventricle, tension members, such as suture lines, can be connected tothe anchor members and placed in tension to draw the inner walls of theventricle into closer proximity.

In one representative embodiment, a device for reshaping a ventricle ofa heart comprises anchor means for anchoring the device to tissue insidethe heart, and pusher means for applying a pushing force against theinside of the ventricle to cause the apex of the heart to move away fromthe anchor means to distend the heart in a direction extending from thebase of the heart to the apex.

In another representative embodiment, an apparatus for altering a shapeof a heart comprises a tension member having first and second endportions. A first anchor member is connected to the first end portion ofthe tension member and comprises a plurality of radially self-expandingtissue engaging members that are configured to anchor themselves totissue at a first location inside the heart. A second anchor member isconnected to the second end portion of the tension member and comprisesa plurality of radially self-expanding tissue engaging members that areconfigured to anchor themselves to tissue at a second location insidethe heart. The tension member is placed in tension between the first andsecond anchor members such that inner walls of the heart are drawntoward each other to alter a shape of the heart.

In another representative embodiment, a method for reshaping a dilatedventricle of a patient comprises applying a longitudinal force againstan apex portion of the ventricle to elongate the ventricle. The forcecan be applied by deploying a reshaping device inside the dilatedventricle. The reshaping device is configured to apply a pushing forceagainst an inner surface of the ventricle at the apex to cause theventricle to elongate. Alternatively, the longitudinal force can beapplied to the apex portion by securing a first end portion of a tensionmember to the outer surface of the apex portion and securing a secondend portion of the tension member to a body part below the apex portionto draw the apex portion downwardly and toward the body part, therebyelongating the ventricle.

In yet another representative embodiment, a method for reshaping adilated ventricle of a patient comprises positioning a tension memberhaving first and second ends in the ventricle, securing the first end ofthe tension member to a first inner wall of the ventricle and securingthe second end of the tension member to a second inner wall of theventricle, and tensioning the tension member to draw the inner wallstoward each other.

The foregoing and other features and advantages of the invention willbecome more apparent from the following detailed description, whichproceeds with reference to the accompanying figures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a cross-sectional view of a heart for backgroundpurposes.

FIG. 2 illustrates a cross-sectional view of a heart having a dilatedleft ventricle.

FIG. 3 is a side view of an exemplary embodiment of a reshaping devicethat is implantable in a dilated left ventricle for reshaping theventricle.

FIG. 4 is a cross-sectional view of a heart showing the reshaping deviceshown in FIG. 3 deployed in the left ventricle.

FIGS. 5A-5C are schematic side views showing the reshaping device ofFIG. 3 being deployed from a delivery catheter that can be used todeliver the reshaping device to the implantation site via the patient'svasculature, according to one embodiment.

FIGS. 6A-6C are side views of a variation of the embodiment of FIG. 3illustrating a technique for adjusting the overall length of thereshaping device.

FIG. 7 is a cross-sectional view of a heart showing another exemplaryembodiment of a reshaping device incorporating a prosthetic aortic valvethat is deployed within the native aortic valve.

FIG. 8 is a cross-sectional view of a heart showing another exemplaryembodiment of a reshaping device incorporating a prosthetic aortic valvethat is deployed within the native aortic valve and is adapted toprovide a lateral force against the anterior mitral valve leaflet toimprove leaflet coaption.

FIGS. 9A and 9B are cross-sectional views of a heart illustrating atechnique for securing a suture loop to the inner walls of the leftventricle for reshaping the ventricle.

FIG. 10 is a cross-sectional view of a heart showing a reshaping devicecomprising plurality of tension members secured to the inner walls ofthe left ventricle for reshaping the ventricle, according to anotherembodiment.

FIG. 11 is a partial, cross-sectional view of a left ventricle showing acatheter being used to secure suture lines to anchor members secured tothe inner walls of the left ventricle.

FIG. 12 is a transverse cross-sectional view of a left ventricle showinga plurality of suture lines placed in tension across the ventricle forreshaping the ventricle.

FIG. 13A is a perspective view of an exemplary embodiment of an anchormember for a suture line shown in an expanded state.

FIG. 13B is a perspective view of the anchor member of FIG. 13A shown ina compressed state for delivery to the heart.

FIGS. 14A-14C illustrate an exemplary embodiment of a delivery catheterbeing used to deploy the anchor member of FIGS. 13A and 13B.

FIG. 15 is a cross-sectional view of a heart showing tension memberssecured to the outside of the heart at the apex for reshaping the heart,according to one embodiment.

FIG. 16 is a cross-sectional view of a heart showing a tension membersecured to the outside of the heart at the apex for reshaping the heart,according to another embodiment.

DETAILED DESCRIPTION

As used herein, the singular forms “a,” “an,” and “the” refer to one ormore than one, unless the context clearly dictates otherwise.

As used herein, the term “includes” means “comprises.” For example, adevice that includes or comprises A and B contains A and B but mayoptionally contain C or other components other than A and B. A devicethat includes or comprises A or B may contain A or B or A and B, andoptionally one or more other components such as C.

With reference to FIGS. 1 and 4, a four-chambered heart 10 isillustrated for background purposes. On the left side of the heart, themitral valve 12 is located between the left atrium 14 and left ventricle16. The mitral valve generally comprises two leaflets, an anteriorleaflet 12 a and a posterior leaflet 12 b. The mitral valve leaflets areattached to a mitral valve annulus 18, which is defined as the portionof tissue surrounding the mitral valve orifice. The left atrium 14receives oxygenated blood from the pulmonary veins 20. The oxygenatedblood that is collected in the left atrium 14 enters the left ventricle16 through the mitral valve 12.

Contraction of the left ventricle 16 forces blood through the leftventricular outflow tract and into the aorta 40 (FIG. 4). The aorticvalve 28 is located between the left ventricle 16 and the aorta 40 forensuring that blood flows in only one direction (i.e., from the leftventricle to the aorta). As used herein, the left ventricular outflowtract (LVOT) is intended to generally include the portion of the heartthrough which blood is channeled from the left ventricle to the aorta.The LVOT shall include the aortic valve annulus and the adjacent regionextending directly below the aortic valve annulus and the portion of theascending aorta adjacent the aortic valve.

As best shown in FIG. 1, on the right side of the heart, the tricuspidvalve 22 is located between the right atrium 24 and the right ventricle26. The right atrium 24 receives blood from the superior vena cava 30and the inferior vena cava 32. The superior vena cava 30 returnsde-oxygenated blood from the upper part of the body and the inferiorvena cava 32 returns de-oxygenated blood from the lower part of thebody. The right atrium 24 also receives blood from the heart muscleitself via the coronary sinus. The blood in the right atrium 24 entersinto the right ventricle 26 through the tricuspid valve 22. Contractionof the right ventricle forces blood through the right ventricularoutflow tract and into the pulmonary arteries. The pulmonic valve 44(FIG. 4) is located between the right ventricle 26 and the pulmonarytrunk 42 for ensuring that blood flows in only one direction from theright ventricle to the pulmonary trunk. The blood enters the lungs foroxygenation and is returned to the left atrium 16 via the pulmonaryveins 20.

The left and right sides of the heart are separated by a wall generallyreferred to as the septum 34. The portion of the septum that separatesthe two upper chambers (the right and left atria) of the heart is termedthe artial (or interatrial) septum 36 while the portion of the septumthat lies between the two lower chambers (the right and left ventricles)of the heart is called the ventricular (or interventricular) septum 38.As shown in FIGS. 1 and 4, a healthy heart has a generally conical shapethat tapers from a base 46 to an apex 48.

As discussed above, heart disease can cause dilation of the heart,resulting in greatly reduced pumping efficiency of the left ventricle.As depicted in FIG. 2, dilatation causes the posterior wall of the leftventricle to distend outward and the apex to move upward, as generallyshown by arrows A. The dilatation results in a left ventricle having anundesirable round shape, as generally shown in FIG. 2. Heart disease canalso cause dilation of the other chambers of the heart.

According to one aspect, the present disclosure concerns embodiments ofa reshaping apparatus and methods for restoring the conical shape of adilated left ventricle, or at least reshaping the left ventricle to amore conical shape to improve pumping efficiency. In particularembodiments, the left ventricle is reshaped in a non-surgical orminimally-invasive procedure without opening the chest orcardiopulmonary by-pass. The shape of the left ventricle can be alteredby applying a longitudinal force to the apex of the left ventricle tomove the apex downward (relative to the base of the heart), such as bypushing or pulling the apex downwardly. By applying such a force (i.e.,pushing or pulling) on the apex, the left ventricle becomes longer andthinner and thereby achieves a more conical shape. As a result, themuscle fibers are better oriented to accomplish torsional motion of theheart, thereby increasing the efficiency and work capability of the leftventricle. The embodiments disclosed herein can also be used to reshapethe right ventricle of the heart.

With reference to FIG. 3, an exemplary embodiment of a reshaping device50 for reshaping a left ventricle is now shown for purposes ofillustration. The device 50 is configured for deployment within a leftventricle and generally comprises a body having an anchor member 52 andan elongate pusher member, or arm, 54 mounted to the anchor member 52.The pusher member 54 in the illustrated embodiment is a substantiallyJ-shaped member having a proximal end connected to the anchor member andan arcuate, atraumatic flexible tip portion 56 shaped for engagementwith the inner surface of the left ventricle. The pusher member 54 isconfigured for pushing against the inner surface of the left ventricleafter the device 50 is deployed in the left ventricle, as furtherdescribed below.

The pusher member 52 is preferably formed from a round wire or agenerally flat, ribbon-like piece of material. Alternatively, the pushermember 52 can comprise an elongated tubular body that can be formed froma mesh material, such as used to form stents, or a solid(non-perforated) material. The pusher member 50 can be made of anysuitable biocompatible material, such as, for example, stainless steelor a polymer.

In the illustrated embodiment, the anchor member 52 takes the form of aradially compressible and expandable stent that is adapted to expand toa size sufficient to engage adjacent tissue in the heart and anchor thedevice firmly in place. The anchor member 52 can include variousattachment elements (not shown), such as barbs, staples, flanges, andthe like for enhancing the ability of the anchor member to anchor to thesurrounding tissue. In one specific implementation, for example, theanchor member 52 can be sized for deployment within the left ventricularoutflow tract, such as at a location just beneath the aortic valve. Inanother implementation, the anchor member 52 can be configured fordeployment within the mitral valve annulus, within the aortic valveannulus, or within the left atrium.

The anchor member 52 can be a self-expanding or balloon-expandablestent. When a self-expanding stent is used, the stent can be formed froma shape memory material, such as, for example, Nitinol, and can bedelivered using a sheath. After reaching the treatment site, the device50 is advanced out of the distal end of the sheath and the stent 52expands into contact with the surrounding tissue. When in the form of aballoon-expandable stent, the stent can be formed from stainless steelor any of various other suitable materials. The balloon-expandable stent52 can be configured to be crimped to a reduced diameter and placed overa deflated balloon on the distal end portion of an elongate ballooncatheter.

FIG. 4 shows the device 50 deployed in the left ventricle 16. As shown,the anchor member 52 is deployed in the left ventricular outflow tractjust below the aortic valve 28 and the tip portion 56 of the pushermember 54 engages an inferior inner surface portion 80 of the leftventricle. The overall length L (FIG. 3) of the device 50 when deployedis selected such that the tip portion 56 pushes downwardly against theinner surface 80 while the anchor member 52 is secured firmly in placebelow the aortic valve 28. The force applied by the pusher member 54causes the left ventricle 16 to distend or elongate longitudinally in adirection extending from the base 46 to the apex 48. When compared withFIG. 2, it can be seen that the device 50 has reshaped the leftventricle to provide it with a more conical shape. As described above,the resulting conical shape improves the pumping efficiency of theheart. The device also can be configured to be deployed in a dilatedright ventricle 26 for reshaping the right ventricle in an analogousprocedure.

The overall length L of the device 50 can be selected to achieve adesired reshaping of the left ventricle. Increasing the length L of thedevice 50 will increase the change in length of the left ventriclebetween the aortic valve and the apex while decreasing the length L ofthe device 50 will decrease the change in length of the left ventricle.

The anchor member 52 can also be used to help treat mitral valveregurgitation. Regurgitation through the mitral valve 12 occurs when themitral valve fails to close properly, allowing blood from the leftventricle 16 to leak into the left atrium 14. Regurgitation typically iscaused by changes in the geometric configurations of the left ventricle,papillary muscles, and the mitral valve annulus. As shown in FIG. 4, theanchor member 52 can be sized to engage tissue 82 extending from theaortic valve adjacent the anterior portion of the mitral valve 12. Whenthe anchor member 52 is deployed, it applies a lateral force against thetissue 82. This force urges the anterior leaflet 12 a toward theposterior leaflet 12 b for improving leaflet coaption, thereby reducingor eliminating mitral valve regurgitation.

FIGS. 5A-5C schematically illustrate an exemplary embodiment of adelivery catheter 100 for delivering and deploying the device 50 in theleft ventricle. The catheter 100 in the illustrated embodiment isadapted to be used with a device 50 that has a radially self-expandableanchor member 52. The apparatus 100 includes an elongated deliverysheath 102 (the distal end portion of which is shown in FIGS. 5A-5C) anda pusher member, or advancing member, 104 slidably received in the lumenof the deliver sheath 102.

The catheter 100 can be introduced percutaneously into the patient'svasculature (e.g., into a peripheral artery such as the femoral artery)and advanced to the implantation site. In certain embodiments, forexample, the catheter is sized for insertion through a small incision inthe groin and has a length of at least about 80 cm, preferably about 90to 100 cm, to allow transluminal positioning of the shaft from thefemoral and iliac arteries to the ascending aorta in a retrogradeapproach. Alternatively, the catheter may have a shorter length, e.g.about 20 to 60 cm, for introduction through the iliac artery, throughthe brachial artery, through the carotid or subclavian arteries, orthrough a penetration in the aorta itself. In the femoral approach, thecatheter desirably is long enough and flexible enough to traverse thepath through the femoral artery, iliac artery, descending aorta andaortic arch. At the same time, the catheter desirably has sufficientpushability to be advanced to the ascending aorta by pushing on theproximal end, and has sufficient axial, bending, and torsional stiffnessto allow the physician to control the position of the distal end, evenwhen the catheter is in a tortuous vascular structure. Alternatively,the catheter may be passed through a port between ribs in the patient'sthorax above the heart and through an incision in the aortic arch, in aso-called minimally-invasive procedure.

As shown in FIG. 5A, during advancement to the left ventricle, thedevice 50 is initially contained within the delivery sheath 102 with theanchor member 52 retained in a radially compressed state. In theretrograde approach, the distal portion of the delivery sheath 102 isadvanced through the aorta 40 (FIG. 4), across the aortic valve 28 andinto the left ventricle 16 to position the sheath distal end adjacentthe inner surface 80 of the left ventricle. Once properly positioned,the sheath 102 is retracted relative to the pusher member 104 and thedevice 50 to expose the curved tip portion 56, as shown in FIG. 5B. Theoperator pushes the tip portion 56 firmly against the surface 80 todistend the left ventricle and to position the anchor member 52 in adeployment position below the aortic valve 28. As depicted in FIG. 5C,the sheath 102 can then be withdrawn further to advance the anchormember 52 through the distal end of the sheath, thereby allowing theanchor member 52 to expand into contact with the surrounding tissue toretain the device firmly in place with the tip portion 56 bearingagainst the inner surface 80.

The pusher member 54 of the reshaping device 50 can be configured tohave a variable or adjustable length to achieve a desired reshaping ofthe left ventricle. For example, as illustrated in FIGS. 6A-6B, thepusher member 54 can have an inner lumen that receives a dowel or stylet60 that is slidable within lumen. The stylet 60 is preferably asubstantially rigid member that can resist bending or flexing when thedevice is deployed in the heart. The stylet 60 can be inserted into andwithdrawn from the tip portion 56 to adjust the overall length of thedevice 50. In FIG. 6A, for example, the device has an overall length L₁.As the stylet 60 is inserted into the tip portion 56, as shown in FIG.6B, the stylet 60 straightens a segment of the tip portion 56 toincrease the overall length of the device to a length L₂. The stylet 60can be further advanced into the tip portion 56 to increase the overalllength of the device to a greater length L₃. Conversely, withdrawing thestylet 60 from the tip portion 60 allows the segment of the tip portionthat does not contain the stylet to assume a curved shape, therebyshortening the overall length of the device. A detachable, elongatedcontrol member 62, such as a wire, can be attached to the proximal endof the stylet 60 for moving the stylet relative the pusher member 54.The control member 62 can have a proximal end located outside thepatient to allow the surgeon to adjust the length of the reshapingdevice after the device is deployed in the heart.

FIG. 7 shows another embodiment of an implantable reshaping device,indicated at 150. The reshaping device 150 includes a pusher member 152and an anchor member 154 that comprises a prosthetic valve assembly. Thevalve assembly 154 comprises a radially compressible and expandablestent, or frame, 156 that mounts a flexible valve member 158. The stent156 and valve member 158 can be deployed within the aortic annulus toreplace the function of the native valve. Thus, in this embodiment, thestent 156 serves the dual functions of anchoring the reshaping device150 in place for reshaping the left ventricle and supporting the valvemember 158. Once deployed, the pusher member 152 applies alongitudinally directed force against the inner surface 80 of the leftventricle, forcing the apex 48 to move downwardly relative to the base48 to counter the effects of dilation.

The stent 156 in the illustrated embodiment comprises a plurality ofangularly-spaced axial struts, or support members, that extend axially(longitudinally) of the stent. The stent 156 can also include aplurality of axially-spaced, circumferential bands, or struts, attachedto the axial struts. The circumferential struts are formed with multiplebends that allow the stent to be compressed to a smaller diameter fordelivery to an implantation site and expanded to its functional size foranchoring the valve assembly to the native valve tissue. For example,each of the circumferential struts in the illustrated configurationincludes a plurality of linear strut members arranged in a zig-zag orsaw-tooth configuration defining bends between adjacent strut members.

In alternative embodiments, the stent can have other configurations. Forexample, one or more of the circumferential bands can have a curved orserpentine shape rather than a zig-zag shape. Further, the stent caninclude various attachment elements (not shown), such as barbs, staples,flanges, and the like for enhancing the ability of the stent to anchorto the surrounding tissue.

The valve member 158 can have a leafed-valve configuration, such as atricuspid valve configuration. The valve member 158 can be formed fromthree pieces of pliant material connected to each other at seams alignedwith axial struts of the frame 156 to form collapsible leaflets. Thevalve member 158 can be made from biological matter, such as naturaltissue, pericardial tissue (such as bovine, porcine or equinepericardium), a harvested natural valve or other biological tissue.Alternatively, the valve member 158 can be made from biocompatiblepolymers or similar materials.

Various other self-expanding and balloon expandable prosthetic valveconfigurations also can be used. Additional details regarding othervalves that can be utilized are disclosed in U.S. Pat. No. 5,411,552;U.S. Pat. No. 6,730,118 and U.S. Publication No. 2004/0186563, which areincorporated herein by reference.

In yet another embodiment, as shown in FIG. 8, a reshaping device 200comprises a pusher member 202 connected to a prosthetic valve assembly204. The valve assembly 204 includes an outer frame or stent 206 thatmounts a flexible valve member (not shown). In this embodiment, thestent 206 has a generally tubular upper portion 208 that is deployed inthe aortic annulus and a flared or enlarged lower portion 210 thatextends below the aortic annulus and has a larger diameter. The lowerportion may be sized for engaging and applying a lateral force to thetissue 82 below the aortic annulus, thereby urging the anterior mitralvalve leaflet 12 a toward the posterior leaflet 12 b to improve leafletcoaption. In this embodiment, the flexible valve member may be mountedto the stent 206 within the tubular upper portion 208, preferablyadjacent to the native aortic valve. Alternatively, the flexible valvemember may be mounted to the stent within the enlarged lower portion,wherein the valve assembly may have a larger diameter and greater flowarea. Although the prosthetic valve assembly in FIG. 8 is described ascomprising a portion of a reshaping device for treating the leftventricle, alternative embodiments of the prosthetic valve assembly mayalso be configured for use in alternative applications. For example, theflared stent may be used solely as a replacement valve (i.e., without apusher member) configured to support a valve member in the enlargedlower portion 210. As described above, such a configuration provides aprosthetic valve having a valve member with a larger flow area forimproving blood flow through the heart. Additional details regarding aprosthetic valve assembly having a flared stent suitable for use withthe above embodiments can be found in Applicant's co-pending U.S.Publication No. 2007/0061010.

In alternative embodiments, a reshaping device can include a prostheticmitral valve connected to an elongated pusher member. The prostheticmitral valve is deployed within the mitral valve annulus of a dilatedheart and the pusher member extends downwardly therefrom and applies aforce against the inner surface 80 to distend the left ventricle. Theprosthetic valve therefore replaces the function of the native valve andserves as an anchor member for securing the reshaping device in place.

In other embodiments, other types of prostheses that are deployable inthe mitral valve or in the left atrium for treating mitral valveregurgitation can be mounted to a reshaping device. Such prostheses canserve the additional function of anchoring the reshaping device inplace. Details regarding the structure and use of various embodiments ofprosthesis for treating a mitral valve can be found in Applicant'sco-pending U.S. Publication No. 2006/0058871 and U.S. Publication No.2006/0241745, the contents of which are hereby incorporated byreference.

In certain embodiments, apparatuses for reshaping a ventricle cancomprise suture lines or other tension members that pull the walls ofthe left ventricle into closer proximity, thereby countering the effectsof heart dilation. In one implementation, for example, a suture loopextends transversely across the left ventricle and through tissue atopposing locations in the ventricle for pulling the ventricle wallscloser together.

FIG. 9A shows an exemplary embodiment of a catheter 300 that can be usedto apply a suture loop 310 to tissue inside the left ventricle in aminimally invasive procedure. Details regarding the structure and use ofthe catheter 300 are disclosed in Applicant's co-pending U.S.Publication No. 2004/0181238, which is incorporated herein by reference.The catheter 300 can be advanced through the patient's vasculature untilits distal end portion is positioned in the left ventricle. The distalend portion of the catheter is placed against a wall of the leftventricle, such as at a location on the septum 34, and a needle isadvanced from the catheter and through the tissue for advancing a lengthof suture through the tissue. The distal end portion of the catheter isthen placed against an opposing wall of the left ventricle, and anotherneedle is advanced from the catheter and through the tissue foradvancing another length of suture through the tissue, and thus formingthe suture loop 310 extending through tissue of opposing walls of theleft ventricle. The end portions 312 a, 312 b of the suture loop stillconnected to the catheter 300 are pulled taught to pull the opposingwalls of the left ventricle toward each other to reshape the leftventricle from a generally round, dilated shape to a more conical shape.A fastener or connector 314 (FIG. 9B) can be advanced from the catheter300 and over the end portions 312 a, 312 b to secure the end portionstogether. The remaining suture leads extending from the connector 314can then be cut using a cutting member in the catheter 300, thus formingthe loop 310 shown in FIG. 9B. Additional suture loops can be applied atother locations in the left ventricle to assist reshaping the leftventricle. For example, one or more suture loops can be formed above orbelow the suture loop 310 or at the same position as the suture loop310.

In another embodiment, apparatus for reshaping a ventricle comprises oneor more tension members, such as one or more suture lines, that areconnected to tissue at opposing locations inside the ventricle usinganchor members that engage the myocardium of the ventricle. For example,with reference to FIG. 10, a reshaping apparatus comprises tensionmembers 400 a, 400 b, 400 c secured to the ventricle walls using anchormembers 402. A fastener or clip 404 can be provided for attaching thetension members together at a location within the left ventricle. Thetension members are placed in tension between the respective anchormembers and the fastener to draw the walls of the left ventricle inwardto reshape the left ventricle.

The tension members can be made of any suitable biocompatible material,such as traditional suture material. The tension members in someembodiments can be made of an elastomeric material, such aspolyurethane.

In one method of delivering the tension members 400 and the anchormembers 402, a catheter is advanced through the patient's vasculature toposition the distal end portion of the catheter inside the leftventricle. A deployment mechanism of the catheter is used to deploy theanchor members 402 at selected locations on the inner walls of the leftventricle. When advanced from the catheter, engaging elements of theanchor members 402 deploy and embed themselves in the myocardium,thereby securing the anchor members in place. The catheter can then beused to attach tension members 400 to the anchor members 402 and placethe tension members in tension so as to draw the opposing walls of theleft ventricle toward each other.

FIG. 11 schematically illustrates a method of using a catheter 420 forsecuring suture lines to anchor members 402. As shown, a respectivesuture line 422 a, 422 b, 422 c, 422 d, 422 e can be secured to eachanchor member 402. The suture lines can extend through the catheter to alocation outside the body or to a tension-control mechanism of thecatheter. The tension in the suture lines can be adjusted as desired forreshaping the left ventricle, such as by manually pulling on the suturelines or by operating the tension-control mechanism. When sufficientlyreshaped, a clip 424 can be advanced out of the distal end of thecatheter 420 and over the suture lines to secure the suture linestogether. The remaining portions of the suture lines are cut and removedand the catheter is then removed from the body.

FIG. 12 illustrates another method of placing anchor members 402 in theleft ventricle. A transverse cross-section of a left ventricle 16 isshown in FIG. 12. In this embodiment, anchor members 402 are deployed atangularly spaced locations around the inner circumference of the leftventricle. A respective suture line 450 a, 450 b, 450 c, 450 d, 450 e,450 f is secured to each anchor member 402 and to a fastener 424 at thecenter of the left ventricle. The suture lines are placed in tensionbetween the anchor members 402 and the fastener 424 to draw the walls ofthe left ventricle inwardly toward each other. The anchor members 402can be equally spaced around the inner surface as shown to equallydisperse the pulling forces on the inner walls of the left ventricle.

With reference to FIGS. 13A and 13B, an exemplary embodiment of ananchor member 500 is described in detail. The anchor member 500 in theillustrated embodiment comprises a tubular body 502 having a pluralityof elongated prongs, or tissue-engaging members, 504 located at a firstend thereof and a coupling member 506 located at a second end thereof.In the illustrated embodiment, the coupling member 506 takes the form ofa loop.

The elongated prongs 504 are desirably configured to self-expand fromthe compressed configuration of FIG. 13B to a “flowered” or expandedconfiguration of FIG. 13A. This flowering is desirably achieved with aself curving area 504 a that deflects the prongs 504 radially outwardfrom the center of the body 502 and rearward toward the second end ofthe body. The prongs 504 are desirably pointed or barbed to facilitatepenetration and engagement with the muscular wall of the heart.

The anchor member 500 can be formed from a single tube of shape memorymaterial, such as, for example, Nitinol. During manufacture, the shapememory material may be cut using a mechanical or laser cutting tool.After cutting the tube, the expanded or flowered shape can be impartedto the memory of the shape memory material with techniques known in theart (e.g. heat setting the shape). Methods for manufacturing the anchormember are described in detail in Applicant's co-pending U.S.Provisional Application No. 60/801,446 [Attorney Docket: PVI-5897PRO],which is incorporated herein by reference. In one preferredconstruction, the anchor member can be formed to have an expandedconfiguration that conforms to the contours of the particular surfacearea of the heart where the anchor member is to be deployed.

The surface of the anchor member 500, including the prongs 504, isdesirably configured to promote tissue growth onto and even into itssurface. In one example this growth is achieved by providing the anchormember with a relatively rough and/or porous surface. Additionally,biological coatings of the types known in the art can be included on thesurface of the anchor member 500 to promote healing and tissue growth.

FIGS. 14A-14C illustrate an exemplary method of deploying the anchormember 500 using a delivery catheter 510. As shown in FIG. 14A, theanchor member 500 is disposed in the distal end portion of an outersheath 512 of the delivery catheter 510. A pusher member, or shaft, 514extends coaxially through the deliver sheath 512 and has a distal end incontact with the anchor member 500. The anchor member and pusher memberare slidably received within the outer sheath 512. The outer sheathmaintains the anchor member in a compressed configuration duringdelivery to the implantation site.

The anchor member 500 can be delivered to the heart percutaneously in aretrograde or antegrade approach, or alternatively, it can be insertedthrough an incision in the chest, through the cardiac tissue and intothe left ventricle. When the anchor member is properly positioned at adesired target location within the left ventricle, the outer sheath 512is retracted relative to the pusher member 514 and the anchor member500, as illustrated in FIGS. 14B and 14C. As the anchor member 500advances from the open end of the sheath, the prongs 504 expandoutwardly. In certain embodiments, the expansion of the prongsadvantageously pulls the anchor member 500 out of the sheath 512.

As the prongs 504 exit the outer sheath 512, the prongs 204 expand,bending back towards the body 202 while grabbing nearby heart tissue.The action of the prongs engaging and embedding themselves in the tissuemaintains the anchor member 500 in a stable position within the heartand resists against movement from heart beats, blood flow, and similaractions. In this respect, the anchor member 500 “self-deploys” withinthe heart, requiring little or no extra pressure from the deliverydevice 510 to anchor within the muscular wall of the heart.

After implantation in the heart, tissue grows over the anchor member500, preferably leaving only the coupling member 506 exposed within theleft ventricle. It has been found that adequate tissue growth over theanchor member 500 can occur in two or three weeks. However, the amountof time required may depend on various factors such as the particulardeployment location of the anchor member 500, the surface features orcoatings of the anchor member 500, and/or the condition of the patient.

The coupling member 506 provides a point of attachment for connecting atension member. A tension member can be connected to an anchor memberimmediately following deployment of the anchor member in the heart.Alternatively, in some cases, it may be desirable to allow for asuitable time period for tissue to grow over the anchor member before atension member is connected to the coupling member 506 of the anchormember.

With reference now to FIG. 15, another exemplary reshaping apparatus 600configured to reshape the geometry of the heart is illustrated. In thisembodiment, one or more tension members, or tethers, 602 (e.g., suturelines) are provided for pulling downward on the apex of the heart. Inthe illustrated embodiment, the upper ends of the tension members 602are attached along the apex 48 of the heart (e.g., to the outside of theheart muscle) using a single anchor member 604 as shown or using arespective anchor member 604 for each tension member 602. The anchormember 604 can have a construction similar to the anchor member 500described above. The lower ends 606 of the tension members can be fixedor tied off to a rigid structure within the body, such as a rib.Sufficient tension is applied to the tension members 602 to apply alongitudinal force to the apex that pulls the apex downwardly relativeto the base of the heart. As can be appreciated, applying a pullingforce to the outside of the heart is effective to reshape the geometryof the left and right ventricles.

FIG. 16 shows a reshaping apparatus 700, according to anotherembodiment, that applies a force to the outside of the heart forreshaping the geometry of the heart. The apparatus 700 in theillustrated embodiment comprises a patch 702 that can be secured to theouter surface of the heart muscle along the apex 48. In one exemplaryembodiment, a bioglue may be used to secure the patch 702 to the heart.A tension member 704 (e.g., a suture line) has an upper end 706 securedto the patch 702 and a lower end 708 that can be fixed or tied off to arigid structure within the body, such as a rib. When securing the endsof the tension member, sufficient tension is applied to the tensionmember to pull the apex downwardly relative to the base of the heart toreshape both the left and right ventricles.

In view of the many possible embodiments to which the principles of thedisclosed invention may be applied, it should be recognized that theillustrated embodiments are only preferred examples of the invention andshould not be taken as limiting the scope of the invention. Rather, thescope of the invention is defined by the following claims. I thereforeclaim as my invention all that comes within the scope and spirit ofthese claims.

I claim:
 1. An apparatus for altering a shape of a heart comprising: atension member having first and second end portions; a first anchormember connected to the first end portion of the tension member andcomprising a plurality of radially self-expanding tissue engagingmembers that are configured to anchor themselves to tissue of an innerwall at a first location inside the heart; and a second anchor memberconnected to the second end portion of the tension member and comprisinga plurality of radially self-expanding tissue engaging members that areconfigured to anchor themselves to tissue of an inner wall at a secondlocation inside the heart; wherein when the tension member is placed intension between the first and second anchor members, the inner walls aredrawn toward each other to alter a shape of the heart.
 2. The apparatusof claim 1, wherein the tension member comprises a suture line.
 3. Theapparatus of claim 1, wherein the anchor members are self-deploying. 4.A method for reshaping a dilated ventricle of a patient comprising:positioning a tension member having first and second ends in theventricle; securing the first end of the tension member to a first innerwall of the ventricle and securing the second end of the tension memberto a second inner wall of the ventricle; and tensioning the tensionmember to draw the inner walls toward each other.
 5. The method of claim4, wherein the tension member comprises a suture line.
 6. The method ofclaim 4, wherein the first and second ends of the tension member aresecured to the inner walls with respective expandable anchor members. 7.The method of claim 6, wherein each anchor member comprises radiallyexpandable prongs that grab the tissue of the inner walls to secure theends of the tension member in place.
 8. The method of claim 4, wherein:the tension member comprises a first tension member; and the methodfurther comprises securing the first end of a second tension member tothe first inner wall, securing a second end of the second tension memberto the second inner wall, tensioning the second tension member, andconnecting the first and second tension members to each other at alocation between the inner walls.